Method of making cheese having zones of different characteristics

ABSTRACT

Cheese having zones of contrasting characteristics is prepared by filling a cheese vat with milk, inserting in the vat a partition that prevents free fluid interchange between parts of the vat to divide the milk into separate parts, treating the different parts of milk so that cheese made from one part will exhibit characteristics different from those of cheese made from milk of another part, treating each part to form a mass of curd and whey, removing the partition to unify the interior of the vat, cutting the curd of each part and stirring the pieces of curd until the pieces of all parts of the vat are mixed throughout the vat.

TECHNICAL FIELD

This invention relates to cheesemaking in general and, in particular, toa method for making cheese having discrete zones exhibiting contrastingcharacteristics.

BACKGROUND OF PRIOR ART

The prior art is generally cognizant of cheese having discrete zonesexhibiting contrasting characteristics. For example, cheese has beenmade in which contiguous parts of the cheese have contrasting colors sothat the cheese has a mottled or dappled appearance. Such cheese hasachieved wide consumer acceptance. To make such cheese, cheese factoriesconventionally employ two cheesemaking vats. Milk is introduced intoeach vat and is acidified, generally by the introduction of a selectedbacterial culture for the production of lactic acid. Then the contentsof the two vats are treated in disparate manners. In the example ofcheese having zones exhibiting contrasting colors, a cheese coloringagent may be added to one vat and not to the other. Thereafter acoagulum or curd is formed in both vats, usually through the addition ofrennet. The curd is cut with curd knives in the conventional manner, andthe curd pieces and whey of each vat are mixed and heated in order todrive whey out of the curd. The pieces of curd are subsequently washedwith water, cooled, and salted before being put into cheese forms andpressed to their final shapes.

At some selected point after the initial formation of curd and beforethe pieces of washed curd are put into cheese forms, the pieces of curdfrom the two vats are mixed. It is thus necessary to shovel or otherwisephysically transfer the contents of one vat into the other. This is atime-consuming, difficult, and costly step. In addition, care must betaken that the pieces of curd are not unduly crumbled while beingshoveled or otherwise transferred from one vat into another.

Thus, the conventional mixing of contrasting pieces of curd in order toproduce cheese having discrete zones involves unusual expenditures.Labor not otherwise needed in cheesemaking must be expended to transferthe curd from one vat into another. Furthermore, at least two vats arerequired to be used by the conventional method, further limitingavailability of the method.

BRIEF SUMMARY OF THE INVENTION

The present invention is summarized in that a method for making cheesehaving discrete zones exhibiting contrasting characteristics includesthe following steps: A cheese vat is filled with milk having a selectedtemperature and acidity. A vat divider is inserted to divide theinterior of the vat into parts of selected relative size and to preventfree fluid interchange between the parts. The milk in each of the partsis then treated in a distinctive manner selected to cause cheese madefrom the milk of one part to exhibit selected characteristics differingfrom those exhibited by cheese made from the milk of the other part.Then the milk of each part is treated to form a mass of coagulum or curdand whey, the curd in each part exhibiting distinctive, selectedcharacteristics. The vat divider is removed after the formation of thecurd, and the entire mass of curd is cut with curd knives to producepieces of curd of a selected size. Then the whey and pieces of curd arestirred until the pieces from all parts of the vat are mixed throughoutthe vat.

A primary object of the invention is to provide a method for makingcheese having discrete zones exhibiting contrasting characteristics.

A second object of the invention is to provide a process for making suchcheese in which only one cheese vat need be used.

Another object of the invention is to provide a process for the makingof such cheese in which the cut curd need not be subjected to additionalhandling which might cause increased crumbling or breakage of the curdpieces.

A further object of the invention is to provide a process for the makingof such cheese in which the labor requirements for the making of thecheese will not significantly exceed those for making cheese not havingdiscrete zones exhibiting contrasting characteristics.

Another object of the invention is to provide a process for making suchcheese in which necessary modifications of existing cheese vats andadditions to existing cheesemaking equipment will be minor andinexpensive to accomplish.

Other objects, features, and advantages of the invention will beapparent from the following detailed description taken in conjunctionwith the accompanying drawing showing a preferred embodiment ofapparatus for making cheese having discrete zones exhibiting contrastingcharacteristics.

BRIEF DESCRIPTION OF THE DRAWING

In the drawing:

FIG. 1 is a perspective view of a vat used in the method of theinvention with a part of the wall of the vat being broken away.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring more particularly to the drawing, FIG. 1 shows a cheese vatfor carrying out the method of the invention generally at 10 havingopposing, interiorally facing sides 12 and ends 14 and a bottom 16. Aremovable, solid, fluid-impervious partition or vat divider 18 isadapted to divide the vat 10 into two parts of selected relative size.The vat divider 18 is held in substantially rigid, removable relation tothe vat 10 by a suitable means for holding the divider. In the preferredembodiment, two opposed pairs of braces 20 extend vertically on thesides 12 for a selected distance and project into the vat 10 for aselected distance. Each pair of braces 20 defines between them avertically extending divider slot 22 having a size selected to admit thevat divider 18 when the vat divider 18 is inserted into the slots fromabove the vat 10. The outer periphery of the vat divider 18 is adaptedto conform closely to the inner surface of the vat 10 to substantiallyprevent free fluid interchange between the two parts of the vat 10 whenthe vat divider 18 is held in place by the braces 20. Resilient means(not shown) may be employed between the outer periphery of the vatdivider 18 and the inner surface of the vat 10 to provide a better seal,if it is desired to substantially completely separate the two parts ofthe vat.

The braces 20 may be permanently fastened to the sides 12. However, itis preferable that they be removable in order to facilitate cleaning ofthe vat 10 and to avoid permanent changes of the vat, which may also beused for other purposes. Therefore, the braces 20 preferably are rigidlyattached to a clamp member 24. The clamp member 24 extends over the topof the wall 12 to which the associated braces 20 are to be attached andthen downwardly on the outside of the vat 10 for a selected distancesubstantially parallel to the vat outside wall 25. Means for securingthe clamp member 24 against the outside wall 25 are provided, such asthe hand set screw 26. With the clamp member 24 in place over the sideof the vat 10 and the hand set screw 26 firmly tightened, the associatedbraces 20 are thereby rigidly held against the associated wall 12.

The method for making cheese having discrete zones exhibitingcontrasting characteristics according to the present invention begins ina conventional manner by filling the cheese vat 10 with milk having aselected temperature and acidity, as is common in the art. Preferablythe milk placed in the vat is then acidified to a selected acidity, alsoin a conventional manner.

The next step in the process of the invention is the insertion of thevat divider 18 into the vertically extending divider slots 22. The vatdivider 18 divides the vat 10 into parts of selected relative size, eachpart filled with partially conditioned milk. The purpose of the vatdivider 18 is to prevent free fluid interchange between the parts. Inmost applications the vat divider 18 need not engage the sides 12 andbottom 16 of the vat 10 in fluid-tight relation in order to sufficientlyhinder free fluid interchange for the purposes of the process of theinvention. Instead, it will usually be sufficient if the vat divider 18engages the sides 12 and bottom 16 tightly enough so that the volume ofmilk infiltrating from one part of the vat 10 to the other around thevat divider 18 is small in comparison to the volumes of each part of thedivided vat. Of course, where it may be desirable to substantiallyisolate the parts of the vat interior owing to the nature of thedifferent treatments employed, a more fluid-tight seal between thedivider 18 and the vat 10 may be obtained by use of resilient means aspreviously discussed.

The next step in the process of the invention is to treat theconditioned milk in each of the parts of the vat 10 in a distinctivemanner selected to cause cheese made from the milk of each part toexhibit selected characteristics. Any method of treating milk so as toaffect cheese made therefrom may be used. By way of example only, cheesecolor may be added to the milk on one side of the vat divider 18 and notto the milk on the other side.

The next step of the process of the invention is to treat the milkcontained in each part of the vat 10 so as to form a mass of curd andwhey. Preferably rennet, pepsin, Mucor miehei, Mucor pussillus, orcombinations thereof are added to each part of the vat 10 and mixed inby stirring in a conventional manner in order to cause curd to form inthe milk.

After the curd is well formed, the vat divider 18 may be removed tounify the interior of the vat 10. In addition, the hand set screws 26may be loosened and the braces 20 removed, thereby facilitatingsubsequent operations performed in the vat 10. The coagulum or curd isthen cut with curd knives in the conventional manner, to form amultiplicity of small pieces of curd of a selected size. After the curdis cut, the whey and pieces of curd are stirred until pieces from allparts of the vat 10 are distributed uniformly therein. The stirring maybe accomplished by any convenient means, such as the overhead agitator28 equipped with conventional stirring paddles 30. While it is usuallyadvantageous to remove the vat divider 18 after the curd has beenformed, as described, for ease of carrying out subsequent steps, in someprocesses it may be advantageous to maintain the vat divider 18 in placeduring one or more subsequent treatment steps, depending on the process.In any event, at some point subsequent to forming of the curd thedivider 18 should be removed, after which the curd must be stirred untilthe curd pieces from each part of the vat 10 are distributed throughoutthe vat 10.

After the curd has been cut, the mixture of whey and pieces of curd fromeach of the two parts of the vat 10 are then subjected to conventionalcheesemaking washing and forming processes to make a pressed cheesetherefrom. Typically, the mixture of whey and curd pieces will be heatedand stirred to dispel whey from the curd pieces. The whey will then beremoved from the vat 10, and cold water will be introduced into the vat10 to wash and cool the curd pieces. The water is then removed and thecurd pieces are salted, placed into cheese forms, pressed, and packaged.

The cheese formed by the process of the invention exhibits discretezones, each zone deriving from a piece of curd. Zones deriving frompieces of curd formed in one part of the vat 10 will exhibit thecharacteristics produced by the mode of treatment to which the milk inthat part of the vat 10 was subjected while the vat divider 18 was inplace. More than one vat divider 18 may be employed to divide the vat 10into more than two parts should more than two types of contrasting zonesbe desired. Since the milk in each of the parts was treated in a mannerselected to cause cheese made from the milk of that part to exhibitcharacteristics differing from those exhibited by cheese made from themilk from another part, cheese made by the process of the invention hasdiscrete zones exhibiting contrasting characteristics. If, for example,the milk in one part of the vat 10 has been treated with yellow cheesecoloring while that in the other part of the vat 10 was left uncolored,the cheese made by the process of the invention will exhibit a uniformlymottled, yellow and white appearance.

The process for making cheese of the invention allows a contrasting curdcheese to be made using a single vat 10, and with almost no additionaleffort or cost as compared to conventional uniform cheesemaking. Theprior art teaches only the use of two vats to make such cheese.Therefore, a cheese factory having only one vat that may be devoted tothe making of such cheese may nevertheless make a contrasting curdcheese using the process of the invention, whereas this would not havebeen possible with the prior art two-vat technique. Furthermore, theprior art required the physical transfer of curd from one vat intoanother for mixing. This necessitated the expenditure of considerablelabor and was done at some risk of crumbling or breakage of the piecesof curd. In contrast, by using the process of the invention, curd ofdiffering characteristics may be formed within a single vat 10, makingunnecessary the transfer of curd from one vat to another. Considerablesavings of time and money result.

The following is an example of the performance of the method of thepresent invention, but it is understood that the invention is notlimited to the particular method, constituents, and product example butembraces all variations thereof as come within the scope of the claimswhich follow thereafter.

EXAMPLE

A cheese vat was filled with milk having a temperature of 87° to 89° F.and 0.16% to 0.18% acidity. A lactic acid-producing cheese bacterialculture was added to the milk, along with the commercially availablecheese culture known as Marschall Thermostar and sold by MarschallDivision, Miles Laboratories, Inc. The bacterial culture was allowed toreproduce until the milk was brought to 0.18% to 0.20% acidity. A vatdivider was inserted into the vat to divide the vat into approximatelyequal parts. Yellow cheese color was added to the milk of only one partof the vat and was mixed into the milk of that part by stirring. Themilk in the other part of the vat was allowed to remain uncolored.Cheese rennet was added in equal portions to each part of the vat andwas mixed with the milk. Curd was allowed to form. Approximately 20 to40 minutes after the formation of the curd, the vat divider was removedto unify the interior of the vat, and the curd was cut with curd knivesinto cube-shaped curd pieces measuring approximately three-eighths inchto the side. The whey and the curd of both parts of the vat were thenmixed together by the use of an agitator equipped with stirring paddles.The curd was stirred and heated to 98° to 102° F., with that temperaturemaintained for 25 to 30 minutes to dispel whey from the curd. Fifteen tothirty minutes after heating was accomplished, the whey was drained fromthe vat. The curd was then stirred with the agitator until it exhibited0.18 % to 0.20% acidity. Cold water was introduced to the vat and thecurd was washed and cooled thereby to 84° to 86° F. The water was thenremoved from the vat, and the curd was stirred with the agitator untilit exhibited 0.22% to 0.26% acidity. The curd was then salted, put intocheese forms, pressed, and packaged. The cheese made by this exampleexhibited discrete zones having contrasting colors, yellow and white.

What is claimed is:
 1. A method for making cheese having discrete zonesexhibiting contrasting characteristics comprising:(a) filling a cheesevat with milk, (b) dividing the vat into parts of selected relative sizeand preventing free fluid interchange between the parts by inserting apartition of solid, substantially fluid-impervious material within thevat in close engagement with the inside surface of the vat, (c) treatingthe milk in each of the parts in distinctive manners selected to causecheese made from the milk of one part to exhibit selectedcharacteristics differing from those exhibited by cheese made from themilk of another part, (d) treating the milk of each part to form a massof curd and whey, the curd in each part exhibiting distinctive, selectedcharacteristics, (e) unifying the interior of the vat after formation ofthe curd by removing the partition from the vat, (f) cutting the curd ofeach part with curd knives to produce pieces of curd of selected sizes,and (g) stirring the pieces of curd at least until the pieces of curdfrom all parts of the vat are mixed throughout the vat.
 2. The methodfor making cheese having discrete zones exhibiting contrastingcharacteristics specified in claim 1 wherein the step of treating themilk in each of the parts of the vat in a distinctive manner includescoloring the milk of one part differently from the milk of another partby adding color to the milk of at least one part.
 3. The method formaking cheese having discrete zones exhibiting contrastingcharacteristics specified in claim 2 further including after the step ofcutting the curd, the steps of heating the contents of the vat to dispelwhey from the curd pieces, removing the whey from the vat, introducingcold water into the vat to wash and cool the curd pieces, removing thewater from the vat, salting the curd pieces, and then removing the curdpieces from the vat and pressing them into selected cheese forms whereinthe curd pieces from each different part of the vat are distributedthroughout in random fashion, and wherein the step of stirring thepieces of curd may be employed at any time after the curd is cut andbefore the curd pieces are removed from the vat.